30. Rhodostemonodaphne synandra

Rhodostemonodaphne synandra van der Werff

Ann. Missouri Bot. Gard. 78: 422, fig. 7. 1991. Type. Ecuador. Napo: Estación Biológica Jatun Sacha, 10 Feb 1986 (stam. fl), Neill & Palacios 7129 (holotype, MO; isotypes, AAU, F, GH, HBG n.v, K, MO, QAME n.v.).

Local names.  Peru: moena negra, and moena amarilla.

Description

Trees: branching unknown; twigs angular, soon becoming terete, ca. 8 mm diam.; epidermis black, barely visible due to indument cover; terminal bud plump, ca. 1 X 1 mm; cataphylls caducous; indument puberulous, caducous after one flush, the hairs dense, up to 1 mm long, straight to curved, erect, golden. Leaves: petioles robust, 2.5–4.2 cm X 0.3–0.6 mm, adaxially flattened; blades chartaceous, flat, broadly obovate to elliptic or oblong, 16–29(–39) X 6–11(–17) cm; base acute to obtuse, 80–130°; apex acute to obtuse, 80–120°, ultimately acuminate for up to 1.5(–2.5) cm; margin plane; primary vein above slightly impressed to flat, below prominent; secondary veins (12–)14–17 pairs, equidistant, brochidodromous, above flat, below prominent, diverging at 45–60°, abruptly arching near margin, chordal angle 45–60°, the angle uniform along blade length; tertiary veins above slightly raised, below raised, conspicuously scalariform; higher order veins above slightly raised, below raised; surface above shiny brown, below dull creamy brown; indument above absent, the primary vein puberulous, below tomentose, the hairs dense, up to 0.4 mm long, straight to curved, erect, yellowish, denser on the veins, persisting for at least two flushes. Staminate inflorescences: along whole length of flush to acrotonic, pendulous, peduncles 10–20 cm long, the hypopodia 3–6 cm X ca. 3.5 mm, branch orders 3, the second-order branches 13–18, dispersed, lowest branch up to 3.5 cm long, color and indument of all axes as on twigs; bracts caducous (not seen); bracteoles persistent or caducous, up to 2 mm long, adaxially glabrous. Staminate flowers: pedicels ca. 1.2 X 1.4 mm, the diameter even throughout; receptacle globose, ca. 4 X 3.6 mm, constricted at the place of tepal inception; tepals coriaceous, ovate, ca. 2.2 X 1.8 mm, at anthesis spreading, yellowish-brown, adaxially puberulous; stamens of whorls I and II loriform, the anthers oblong, ca. 1.6 X 0.6 mm, puberulous, the locelli 4, apical, in a shallow arch, the upper pair introrse, the lower pair latrorse, the glands absent; whorls II and III fused for two thirds of their lengths into a tube; whorl III loriform, ca. 2.4 X 0.8 mm, puberulous, the locelli 4, the upper pair latrorse, the lower pair extrorse, the glands minute, ca. 0.4 mm diam.; whorl IV absent; all stamens reddish-brown; pistillode filiform, ca. 1 X 0.3 mm, glabrous. Pistillate flowers: pistil ca. 4 X 1.6 mm; ovary globose, ca. 2.8 mm long, glabrous. Fruits: pedicels up to 10 X 5 mm, abruptly enlarging to form the cupule; cupule hemispherical, up to 15 X 25 mm, smooth, the margin straight, tepals caducous; berry elliptic, up to 40 X 22 mm.

Field notes

Trees up to 30 m tall and 24 cm diam.; buttresses present; inner bark ca. 8 mm thick. Tepals green.

Distribution (Figure 19)

Eastern foothills of the Andes and adjacent lowlands in Colombia, Ecuador, and Peru; at 250–1600 m elev., in low-montane and lowland rain forest.  Flowers collected in October, January and February.  Ripened fruits found in January together with flower buds.

Additional specimens examined

Colombia. Meta: Tinigüa national park, la Macarena, Mt. Chamusa, 22 Mar 1990 (stam. fl), Stevenson 126 (GH).

Peru. Amazonas: Cenapa, Bagua, 26 Jan 1967 (pist. fl, fr), Tillett 672-83 (GH). Huánuco: Puerto Inca, Llullapichis, DANTAS, 2 Oct 1989 (pist. fl), Kröll-Saldaña 642 (MO). Ucayali: Cordillera Azul, Fundo Cinchona, Km 209 Huánuco-Pucallpa rd., 9 Oct 1944 (pist. fl), Hodge & Lescano 1 (F).

Discussion

Rhodostemonodaphne synandra is unique in having the stamens of whorls II and III fused for two thirds of their lengths into a tube.  This feature is most strikingly seen in the only staminate specimen known (Neill & Palacios 7129), although it is also evident in the pistillate flowers.  Furthermore, the stamens of all three whorls have strap-like (lorate) filaments.  The inflorescences of R. synandra are peculiar in having all branch axes reduced, thus producing an elongated inflorescence with lateral clusters of flowers.  Vegetatively, however, R. synandra cannot be distinguished at first sight from the yellowish, densely pubescent forms of R. kunthiana frequently found on the E Andean slopes in Ecuador and Peru; the yellow-brown pubescence cited by van der Werff in the original description is also found on several other variants of R. kunthiana, in particular the Central American populations as well those east of the Andes in Ecuador.  The variation in leaf shape observed in the few specimens available falls well within the range of R. kunthiana; R. synandra has leaves that in size are comparable to the larger leaves recorded for R. kunthiana.

Contact | Updated 29.07.2005 | ©2005 Santiago Madriñán